The proposal describes a plan to generate a staining reagent for antigen specific CD4 T cells by modifying the MHC tetramer technology. Specifically, the investigators will create an antibody like molecules whose variable regions have been replace with single chain MHC Class II/peptide structures that will bind to autoreactive CD4 T cells involved in MS. The valency of the tetramers generated by this group can be easily manipulated using well-characterized techniques established to multimerize antibodies. The investigators anticipate that, like the existing MHC tetramer, this product will be of use to researchers who wish to identify antigen specific T cells during the course of disease and because of its multimerization characterization may prove even more valuable. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE